Etridiazole is a fungicide and pesticide used for prevention of pythium ultimum on cotton plants.

[2] Etridiazole can be synthesised from acetonitrile as follows: It can also be is produced by the reaction of trichloroacetamidine hydrochloride with trichloromethanesulfenyl chloride, and then with sodium hydroxide in ethanol.

[3] Etridiazole is stable under normal conditions,[4] but degrades upon continuous exposure to sunlight,[5] and is hydrolysed by alkalis.

[6] When heated to decomposition, it emits toxic fumes of hydrogen chloride, sulfur oxides, and nitrogen oxides.

[7] Etridiazole has been classified as a Group B2 Probable Human Carcinogen.